An increasing number of applications today make use of digital video for various purposes including, for example, remote business meetings via video conferencing, high definition video entertainment, video advertisements, and sharing of user-generated videos. As technology is evolving, users have higher expectations for video quality and expect high resolution video even when transmitted over communications channels having limited bandwidth.
To permit higher quality transmission of video while limiting bandwidth consumption, a number of video compression schemes are noted including formats such as VPx, promulgated by Google Inc. of Mountain View, Calif., and H.264, a standard promulgated by ITU-T Video Coding Experts Group (VCEG) and the ISO/IEC Moving Picture Experts Group (MPEG), including present and future versions thereof. H.264 is also known as MPEG-4 Part 10 or MPEG-4 AVC (formally, ISO/IEC 14496-10).
These compression schemes generally break the image up into blocks and may encode a motion vector for each of the blocks on each frame into the resulting digital video bitstream for transmission. Certain techniques are known that re-use a motion vector within a frame. For example, referential encoding in H.264 encodes a motion vector for a block only when there is a difference above a threshold from another block in the same frame. Encoding in VP8 can incorporate techniques known as nearest motion vector (my) and near my that also result in the re-use of a motion vector within a frame. Such techniques are described in, for example, U.S. Patent Publication No. 2004/0228410 A1.